What words would you use to separate influenza spread from Ebola virus disease spread?

I need your help.

I have spent umpteen hours on trying to make this message simple. None of that has been aided by the way that the CDC, the WHO and now the UN use the terms and words confusingly to convey messages to the public. The message is often delivered as if they were sitting around their meeting rooms talking to other health and science professionals. In my opinion, we all look to these guys for simple clear and consistent messages. Right now they need to do much better to convey complex concepts, simply, quickly and more often. Education helps prevent panic, mistakes and conspiracy theories (well-as much as anything can anyway).

So here is another attempt by me to get this wording into line with what the rest of world can make sense of. 

I could also really use your input to make this work - so leave a comment below, or Tweet me @MackayIM or email me or send me a carrier pigeon - with how to make this message simpler for you and your kids and your grandparents and that weird uncle you stay clear of at Christmas, to understand. 

Let's crowdsource a solution to this confusion, help out others and then see if the major public health bodies can come on board.

Propelled droplets versus a cloud of suspended.

This post and issue have been fuelled most recently by the Ebola virus disease (EVD) epidemic but is also fuelled by my experiences in talking to people about the MERS-CoV and influenza A(H7N9) virus outbreaks. They are respiratory viruses while ebolaviruses are not. Different viruses yes, but common concerns for people and to the issues around trying to understand overly technical terms when they are used differently in everyday life. 

Public health speaking is very public.

Public health issues are spoken about on a global stage, more now than ever. It is up to us to better define the right words and use them consistently. That has definitely not happened for "aerosol" and "airborne". 

We professionals can't just sit back and expect our stakeholders to come along with us for the ride - they will get confused when imagery conflicts with lingo and official statements, and when different public organizations disagree with each other or use tiny but significant differences in their language to communicate risks. 

People are not stupid and deserve more respect than they are currently getting from those who should know much, much better about how to work alongside the public (public health and all).  

So what is the problem here? 

Droplets would probably be an ideal word to differentiate from airborne - and it has been used to differentiate the level of precautions of personal protective equipment (PPE) to prevent infections - droplet precautions and airborne precautions - but the evil physicist types have ruined the use of that word for us by introducing droplet nuclei (the part of the aerosol that lingers in the air and can convey those viruses that survive in it, to a new person to infect them). Physicists like technicalities.

So the problem is trying to define a name for that other process that can simply and clearly describe infectious disease transmission of viruses & bacteria that are propelled from/by the sick person, across the gap between them and an uninfected person, measurably infecting the recipient. The name should make clear that it is a different process to the one that sees a person get sick by inhaling infectious viruses or bacteria held aloft by the air, in a cloud, made by a previously ill person, that has been hanging around for perhaps an hour or more. That one is an airborne route of transmission. 

Some people have berated me for talking technicalities and semantics in recent days while I try to better define this. Tough! Water off an influenza-host's back. Words have meaning and impact and useful words are needed. Especially when everyone is freaking out over a disease they have only read about in dramatized books or seen in Hollywood blockbusters. The two processes listed above are distinct and different for some viruses & bacteria. But it is biology and nothing is 100%, except death. 

Some infections, like those leading to influenza, could result from both processes. Some, like Ebola virus disease have never been observed in humans via one route (airborne), whereas there is a defined risk of them occurring by the other (direct contact between a range of virus-laden body fluids propelled onto a mucous membrane). Yes, coughing a tiny barely visible droplet onto someone else's mouth is direct contact between the wet fluids and the mucous membrane.

They two processes are battled differently. We protect ourselves from them differently. And names can tell us about the different levels of risk. But what is that other route to be called? 

I have an idea. First some perspective.

Ways to think of the differences.

A word cloud of ways to think of the
two different processes of spreading viruses
or bacteria that result in infection and disease
in humans.
v2 Thanks to Nina West for good analogy (Fog/Rain)

The idea.

How about we call the process of relatively short (up to about 3m) distance, coughed/sneezed/vomited wet droplet transfer of disease-causing doses of viruses or bacteria, "Propelled"?

Over to you, world.

Some greats from the comments below...

• "void the spray and live another day"
• Only touched by air, no need to care. Where it splatters, that's where it matters

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Evaluating a traveller being considered for Ebola virus disease

From http://www.cdc.gov/vhf/ebola/pdf/ebola-algorithm.pdf

A lot of other content from the United States Centers for Disease Control and Prevention can be found at: http://www.cdc.gov/vhf/ebola/

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The richer end of the world finds creative ways to spread Ebola virus... [UPDATED x2]

ProMED MODERATOR JW SUGGESTED SOME ASPECT OF THIS WAS A HOAX (HEADLINE). 
http://promedmail.org/direct.php?id=20141004.2832236

Amendment: It has been quite correctly noted below, by the moderator in a personal communication (or 4) and by others, that this image was posted or taken from a Dallas/Fort Worth TV (WFAA) station's chopper on 2-Oct. The infected man vomited 28-Sept, as he headed to hospital. 

So let's say about 72-hours had passed while the vomit sat outside on a non-ceramic/steel surface (these are used in controlled lab experiments to show virus stability-perfect world stuff) through multiple cycles of Texan day/night, high/low temperatures. Okay. The power-washing process is thus extremely unlikely to have generated infectious droplets. Risky and ridiculously long period to leave potentially Ebola-laden vomit out in the open of course, but extremely unlikely to be a source of infection during the power-spraying (water-blasting/gurneying). Apologies for adding to the fear-mongering.  -IanM

This from a Tweet sent to me by @LonnieRhea thanks) 

.@kksheld WFFA-8 photo of crew w/ no PPE's spray washing #Ebola vomit off sidewalk. Via @wfaachannel8: pic.twitter.com/9TJzrkJJKQ cc: @fordvox
� Lonnie Rhea (@LonnieRhea) October 2, 2014

So far the Dallas Ebola virus disease case has been a great learning experience for the United States. 

It really does serve to highlight that humans are what make virus outbreaks...become outbreaks. 

Viruses are nothing without us. And we are so eager to oblige in spreading them around.

Hopefully the virus in that vomit had been inactivated by heat, or the nature of the surface it was on or by drying out before being stirred up by a high pressure water blaster. And hopefully they sterilized their shoes and clothes and...sigh.

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It's what falls out of the aerosol that matters....

v2 031014

"Aerosol" is a messy word. It means different things to different people. So does "airborne".

What's in an aerosol?
Here we're talking about a mixture of different sized stuff. Think  of the size range in a handful the sand from a shelly beach.

A cough/sneeze includes big, wet, heavy propelled droplets that quickly fall to the ground or hit your windscreen (hate it when that happens) or your friend's face (they hate it when that happens) down to dried or gel-like "droplet nuclei" that can float in the air for hours, travelling where the wind blows them; and every size in between.

I've also talked about this before, here.

The public rightly get confused about aerosols. And science and physics and medicine have their own defined meanings - sometimes at odds with each other - that may well be out of step with what the public think.

I do wish the the big public health entities would settle on some definitions for these and other words. It would make everyone's life a lot easier.

Direct contact.

When we talk about "direct contact" and Ebola virus transmission, we do include the bigger wetter heavier droplets that might be propelled from of a sick person during vomiting, or coughing as a risk for transmitting virus. 

Even though that is not physical direct contact, and even though the droplets travel across a gap between people - through the air - it is still a direct line from person A (red in the graphic below) to B (blue). If B is too far away, then those droplets fall to the ground before they hit B. The droplets may remain infectious on the ground. That depends on temperature, humidity, surface type and the type and amount of virus.

The airborne route.

Even though it involves a short period of travel through the air, coughing wet droplets directly onto someone's mucous membranes is not an airborne thing. The term "airborne" is reserved for floaty clouds of droplet nuclei. In humans droplet nuclei have not, to the very best of our knowledge and observations and tests, been found to contain doses of Ebola virus that cause disease in humans. Too little virus coughed into the cloud perhaps or too little that survives..it's not known why, but it is pretty clear that in households where a case of Ebola virus disease was residing, only those household members who had direct contact developed disease, and those that breathed the same air but did not have direct contact, did not develop disease. 

While Ebola viruses may be present in floaty clouds of droplet nuclei, or forced to be in a floaty clouds of droplet nuclei under lab conditions with lab viruses at lab virus concentrations, a floaty cloud of droplet nuclei has not been shown to act as a source of acquisition for Ebola virus and resulting disease among humans. Sorry, did I just repeat myself?

Rest in peace.

Please don't say Reston ebolavirus or the Hot Zone. That (by all accounts riveting) book was not a scientific work, it is a dramatized work and the language is colourful and emotive and scary. The Reston ebolavirus event in non-human primates was never proven to be airborne.

Lastly and most recently, an airborne route was not found to play any role in causing disease or infection when Ebola virus infected and uninfected non-human primates were caged near each other. I've written about this and other non-human primate studies here.

To summarize.

Healthcare workers wear face protection(masks and goggles) to prevent their eyes and mouth being hit by wet droplets of virus-laden body fluids while they are in close contact with ill Ebola virus diseases patients. The also wear all-over gowns so that they don't have to sterilize their clothes between each room they move between. Use of protective equipment doesn't need to convey confusing messages about the type of route Ebola virus uses to spread but it's just lacking in enough public discussion via forums the public attend/view. Knowledge is a bit like vaccination - when coverage reaches a certain level, the community is safe (or it's understanding is complete anyway).

And why wouldn't healthcare workers protect themselves from ill patient fluids-however they come into contact with them? For a healthcare worker, body fluids from ill people they are in close and often prolonged contact with, should generally be considered infectious. This is the case whether we're talking about Ebola virus disease, HIV, measles, influenza or something else. Some of those are caused by airborne viruses, some, like Ebola virus and HIV, not.

Below is my latest attempt at trying to make all those words into a picture. 

If you have ways that can help me make this even simpler - please pass them along (thanks @chrisfharvey).

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Australia's response to Ebola virus disease in West Africa: is too little enough?

Written by Dr. Katherine E. Arden and Dr. Ian M. Mackay

The outbreak of Ebola virus disease (EVD) began in December 2013 in Guinea. It spread to Sierra Leone, Liberia, Nigeria and Senegal. The last two countries on that list were able to contain EVD because they had functioning healthcare systems with doctors and nurses, protective equipment and hospitals that work. The United States of America (US) had its first imported cases arrive 30th September. To some extent, these final three countries could �see it coming�. None of these preparations were in place or possible in Guinea, Sierra Leone or Liberia. They are hosting the largest EVD outbreak in recorded history.

Help wanted.

On August 8th, this epidemic was labelled by the World Health Organization (WHO) as a Public Health Emergency of International Concern (PHEIC). The time for help to arrive and be effective is now. Before 70% of the predicted hundreds of thousands of cases to become infected by this variant of Zaire ebolavirus die. Money is required, and Australia has now donated eight million dollars. Three weeks ago a one billion dollar cost was forecast; a ten-fold increase in a month.[6] But what is really needed urgently are people. People to create beds through the building of treatment facilities, people to staff those facilities to provide the best supportive care possible under the circumstances, people to be trained to safely care for the sick and dying and to trains others, people to track cases, people to help educate family members in how to care for a sick loved one, people to help the psychologically traumatised try and deal with the loss of their children, their parents, siblings, cousins and friends. People are what�s needed. The United Nations (UN), which includes Australia, unanimously adopted Resolution 2177(2014) on the 18th of September within which it provided some instructions to member states. One of those is:

�8.   Urges Member States, as well as bilateral partners and multilateral organizations, including the AU, ECOWAS, and European Union, to mobilize and provide immediately technical expertise and additional medical capacity, including for rapid diagnosis and training of health workers at the national and international level, to the affected countries, and those providing assistance to the affected countries, and to continue to exchange expertise, lessons learned and best practices, as well as to maximize synergies to respond effectively and immediately to the Ebola outbreak, to provide essential resources, supplies and coordinated assistance to the affected countries and implementing partners and calls on all relevant actors to cooperate closely with the Secretary-General on response assistance efforts;�

Australian Prime Minster Tony Abbott noted to the UN that �We were one of the first countries to arrive with help in Japan after the 2011 earthquake; and in the Philippines after the 2013 typhoon.�[5] Why haven�t we arrived in West Africa yet?

Australian Foreign Minister Julie Bishop said on 29th of September, that Australia has not been specifically asked by the WHO to provide healthcare professionals to help.[2] But we a member state of the UN and the WHO is the United Nations� public health arm. In that article the Minister was quoted as saying that we were unable to repatriate infected Australians safely, with this being an integral reason behind our limited response to the Resolution. 

Lightbulb Moment.

Until the Foreign Minister�s comment, the importance of the US concept of building a smaller, healthcare worker-specific treatment facility in West Africa was perhaps lost on the two of us. Such an elitist construction looked bad to the people of the region and, without sufficient background, to others outside it. However, if such a facility reduces or removes the need to spend tens to hundreds of thousands of dollars per person [3] to send them home for treatment, then it seems like a brilliant plan. That money could be better spent, and the added healthcare should help attract more international healthcare workers to the region. In fact, why doesn�t Australia assemble the components and airlift a similar facility, flat-packed, to one of the regions in need of our help? This could be done in a jiffy with Australian military precision. Once built, this facility may well remove the need to repatriate any Australian healthcare professional who may get infected. This may be a better and faster solution than us trying to use British or US facilities or doing a deal with them to evacuate our people. 

A good global citizen.

Prime Minister Abbott noted �That is what you�d expect from a country such as Australia which always wants to be the best global citizen�.[4] We are currently not being the best global citizens that we could be.

Let�s not hide behind excuses. Do we want our national character to be stingy and afraid or strong, generous and willing to give a fair go to those in need? We pride ourselves on our innovative character. We can use this to find a way around problems, real or perceived, in answering the UN�s call for help. Help we are able to provide. 

It would be difficult, heartbreaking, hard work. We know that Aussies are more than capable of doing that. In fact, the more people on the ground, helping, the easier the burden would be. There may be some problems, and it would be naive to expect otherwise. That is why the UN has called for help. If there were no risk, and everything was simple and easy, this situation would not exist in the first place. Should a healthcare worker fall ill, there is a high chance they would die. A tragedy for their family, friends and workmates. And let�s be real, there are more risks to healthcare workers than just Ebola virus disease in these countries. There are scared and sometimes violent villagers, as well as plenty of other diseases like malaria to contend with. 

The lucky country.

Australians have the wealth, the innovation, the ability, the equipment and the skills in our excellent health care workers, engineers, keepers of the peace and logistical organisers. We have the willing volunteers. 

How much of our global village has to burn down before we do more than buy a bucket? Why must we focus on security threats, economic impact, terrorism and political stability when it is the humanitarian aspects that should our priority? Yes, this seems to be the only way to communicate with politicians. But is the way forward for us as a nation that something has to be become a direct threat to us and our lucky country way of life before we lend a hand? Is that who we want to be? Can we not expect a more human perspective from our leaders and ourselves? We think we can. 

References

1. http://www.who.int/mediacentre/news/statements/2014/ebola-20140808/en/
2. http://www.theguardian.com/world/2014/sep/29/australia-cannot-bring-health-workers-home-from-african-ebola-zones
3. http://www.cidrap.umn.edu/news-perspective/2014/09/very-few-aircraft-equipped-evacuate-ebola-patients
4. http://www.news.com.au/national/medecins-sans-frontieres-slams-australias-ebola-response/story-fncynjr2-1227061379772
5. http://www.pm.gov.au/media/2014-09-25/address-united-nations-general-assembly-united-nations-new-york
6. http://www.unmultimedia.org/radio/english/2014/09/one-billion-dollars-needed-to-contain-ebola-outbreak/#.VCv3i_na6-0

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The United States of America is the 6th country to host a 2014 West African Ebola virus variant..

v4 08102014 07:00am AEST

First thing...

CALM DOWN!

This (announced 30-Sept) is the first case of Ebola virus infection to arrive in the United States that was not deliberately flown in. Its not the first viral haemorrhagic fever case though (1 case of Marburg virus disease and at least 4 Lassa virus infections and the Reston ebolavirus outbreak among imported animals[3,5]), and none of the earlier infections resulted in secondary transmission among humans; no-one else got infected from by the case.[4]

Countries that have hosted people infected
with the Ebola virus variant causing the
& 2014 West African Ebola virus
disease epidemic.
Click on image to enlarge.

The male is in critical condition.
When he flew from Liberia to the United States (finally arriving in Dallas,Texas). The man was not showing signs of disease when leaving Liberia or on the plane or immediately after arriving.[6]

This means that the man was not infectious - he could not spread it to fellow travellers or airport workers - because it is well known that disease in another does not develop due to virus being shed before disease is obvious in the infected person.

Briefly[1,2]:

• 19th: Departed Liberia, checked and found to be symptom-free
• 20th: Arrived in Dallas, US (Brussels to Washington on United Airlines 951, then to Dallas Fort Worth on 822 [7])
• 24th: Started to develop symptoms
• 26th: Initially sought care for fever and abdominal pain (not vomiting). Sent home with antibiotics.[8]
• 28th: Admitted to Texas Health Presbyterian hospital in Dallas, Texas. Vomited as leaving home to get into ambulance.
• 30th: Texas public health laboratory found Ebola virus this morning of 30th Sept. CDC received samples, tested and confirmed as Ebola virus disease
• CDC announced case
• 1st Oct: WHO announced case
• Patient is ill and is under intensive care

US family and community contacts (a "handful") are known or being traced and will be under observation/monitoring for 21-days (~21-Oct) for fever. Will any become positive for Ebola virus? Perhaps. I look to Port Harcourt (Nigeria) for some comfort. There were around 60 "high risk" contacts of there and they did not all become ill.

The man identified his country of recent origin, Liberia-the country carrying more cases of Ebola virus disease than any other in history, to a triage nurse on the 26th when he first reported to the Texas Health Presbyterian Hospital. That the information was not passed along sufficiently.[7] While the signs and symptoms were non-specific-all sorts of infectious agents could cause fever and gut issues-the travel history should have been a very important red flag. 

He was sent home with antibiotics. Many acute febrile illnesses are viral  in nature, and antibiotics do not treat viral infections, just bacterial ones but do a great job at helping out antibiotic resistance. Sigh.

So now we have evidence that supports all those talking heads (me included) who noted that it was possible for sporadic cases of EVD to be imported into countries outside of those in West Africa (Guinea, Liberia, Sierra Leone, Nigeria, Senegal). It also, sadly, shows how human infectious disease are - literally by infecting us and using us to cough, vomit and bleed the bug onto to another person, but also figuratively in the roles we play in helping that spread to happen.

Soon, I very much believe, we will also have evidence that in richer countries with functioning healthcare systems, a good knowledge of what is needed to contain virus infections spread by all possible routes, stocks of the necessary personal protective equipment needed to protect healthcare workers from nosocomial infections and the training to use those stocks...that even when unexpected Ebola virus disease cases arrive or incubate and emerge, they will not result in outbreaks.

References...

1. https://www.youtube.com/watch?v=6Bxencye1cg&feature=youtu.be
2. http://www.nytimes.com/2014/10/01/health/airline-passenger-with-ebola-is-under-treatment-in-dallas.html?partner=rss&emc=rss&smid=tw-nytimes
3. http://scienceblogs.com/aetiology/2014/08/02/ebola-is-already-in-the-united-states/.
4. http://blogs.scientificamerican.com/molecules-to-medicine/2014/09/30/ebola-in-usno-need-to-panic/?WT.mc_id=SA_sharetool_Twitter
5. http://www.cdc.gov/media/releases/2014/s930-ebola-confirmed-case.html
6. http://news.sciencemag.org/health/2014/09/one-more-ebola-question-dr-frieden-answers-journalists-would-have-first-u-s-case?rss=1
7. http://www.usatoday.com/story/news/nation/2014/10/01/hospital-ebola-patient/16527143/
8. http://www.usatoday.com/story/news/nation/2014/10/01/texas-ebola-patient/16525649/

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The numbers are underestimates...

Ebola virus numbers.

Sorry but D'uh - yes the numbers during the Ebola virus disease (EVD) outbreak happening since December in Guinea then progressing to Sierra Leone, Liberia, Nigeria and Senegal....are an underestimate. 

Of course they are! 

How could they possibly not be?

Have you not watched a single documentary or news video detailing how heartbreakingly difficult it is to visit and help the people of West Africa, to characterize and gather those case numbers, to take, transport and test samples?

The suspect cases are an underestimate. 
The probable cases are an under-estimate. 
The fatal cases are an under-estimate. 

The only thing that is spot on is the laboratory confirmation numbers, because they are what they were when someone wrote them down having had some semblance of control over the steps to acquire them. 

But let's put that underestimation into context. 

"The tip of the iceberg"
Image originally provided by Gregory Haertl, WHO.
Click to enlarge

Influenza case numbers each year are also an under-estimate. 

In fact, some of those, the subtyping numbers, are deliberately so because it's too expensive and wasteful to subtype every single laboratory confirmed case - so a sample of cases are tested and that is assumed to reflect the subtype distribution for that region during that period. 

But seasonal influenza case numbers as a whole are a huge underestimate. Influenza does not drive everyone to a general practitioner nor to a hospital. Some infections with influenza virus don't even produce noticeable symptoms at all. They are still infections. They just don't get counted. So influenza A virus, possibly the most tracked of any respiratory virus, is underestimates. And that's okay. 

Well, measles too, in the respiratory virus department. 

The latest big bad is the species D enterovirus 68 (EV-D68). But the paltry few detections of it (identified by genotyping) that have reported across the United States are likely a monstrous underestimate. In fact we have very little idea of a normal denominator for EV-D68 detections so it's hard to even know if 2014 is seeing all that big a change in its spread and distribution. Usually the enteroviruses (includes rhinoviruses) cause common cold-like illnesses and only get sought out in the great detail from a research point of view.

Middle East respiratory syndrome coronavirus (MERS-CoV) cases or the emerging influenza A(H7N9) virus cases are all underestimated as well. 

The population of your state or country is an underestimate too you know?

This is because we cannot capture every single case of infection, or person, at once. 

So the next time you are about to say "the WHO numbers are an underestimate" as if that is a revelation or an unexpectedly horrible thing you can also lay at their doorstep - please just don't. It's not smart, new or unusual.

You might as well say the world is round; underestimation of infection numbers is just that well established a fact. It's just by how much, and frankly that doesn't even matter too much because the trends can usually be easily seen, or quickly extrapolated.

Perhaps you did not know all that before. But if you have read to here, you do now.

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The control gap...

v2 300914

I have a theory.

This theory is meant only to apply to disease outbreak/epidemic/pandemic situations, and then only to those which include fatal cases.

This theory of mine has only emerged since I've been plotting Ebola virus cases numbers from the West African epidemic. I precede the explanation with the caveat that there is very probably already a well developed, well-known actual epidemiology term to describe this theory. But I'm not a trained epidemiologist and this is just a blog, so please forgive me my ignorance.

The theory goes that when a gap grows between the number of new cases being reported and the number of deaths or laboratory confirmations in that population, despite the outbreak having been going for a while, this represents an indication that control of the situation is slipping, or has been lost. 

Mind the gap.

This "control gap" - my term, so don't expect to find it anywhere official or that knows of that which it speaks - can also appear when looking at suspected or probable cases of disease X, and the number of those that have been confirmed by a laboratory test.

Other explanations for the control gap may exist of course; testing may be scaled back deliberately, reporting of deaths may have been deliberately throttled for some political reason. So it may not reflect being "out of control" as much as someone else being "in control".

Probably still more variations that I have not thought of at all.

Ebola virus disease (EVD) in Liberia.

In the graphics below I've used the accumulation of World Health Organization data for Liberia, up to 23-Sept. 

First up - the fold increase in total case numbers (suspect+probable+laboratory confirmed) compared to the fold-increase in the distance between that total and the total number of laboratory confirmed cases alone. This distance, or the "control gap|lab", has widened over time. It has widened because total cases have climbed more steeply than the number given a laboratory confirmed diagnosis of EVD. 

For whatever reason(s), laboratory confirmations are not keeping pace with the total case numbers, and they seemed to start slipping at the end of July. 

I suspect a principal reason - and I'm not on the ground of course, so this is all speculation and second-hand knowledge - is that laboratory capacity is overwhelmed. 

Other reasons include that samples might not always be collected or that many recent clinically defined EVD cases are actually due to something clinically similar to EVD, but not an Ebola virus infection. If it were this last one though, the total numbers would be readjusted downwards as new diagnoses were made...if the laboratory has time to make those of course...so I doubt it as a major role.

The control gap|lab
A.) Ebola virus disease case graph for Liberia showing the accumulation of total (suspect+probable+laboratory confirmed) cases (pink line; left y-axis) and deaths (blue line; left y-axis), the laboratory confirmations (green line; left y-axis) and the proportion of fatal cases (right y-axis) at each reporting date (x-axis). The size of the gap between laboratory confirmed cases and total cases is indicated for a range of reporting dates, using a vertical green drop-line.

B.) The drop-lines have been copied and aligned and the amount they have grown has been measured using a scale bar so that the fold-increase can be compared to the first reporting date used, 8-July. The fold-increase value is written at the top of each drop-line. Along the bottom (enclosed within a grey box) are the case numbers at each reporting date examined and the fold-increase (in bold) compared to the 8-July baseline.

Next up -the fold increase in total case numbers (suspect+probable+laboratory confirmed) compared to the fold-increase in the distance between that total and the total number of deaths. The control gap|deaths comparison finds that the deaths and the total cases don't diverge as much as total cases and lab confirmations do. 

The control gap|deaths
A.) Ebola virus disease case graph for Liberia showing the accumulation of total (suspect+probable+laboratory confirmed) cases (pink line; left y-axis) and deaths (blue line; left y-axis), the laboratory confirmations (green line; left y-axis) and the proportion of fatal cases (right y-axis) at each reporting date (x-axis). The size of the gap between laboratory confirmed cases and deaths is indicated for a range of reporting dates, using a vertical blue drop-line.

B.) The drop-lines have been copied and aligned and the amount they have grown has been measured using a scale bar so that the fold-increase can be compared to the first reporting date used, 8-July. The fold-increase value is written at the top of each drop-line. Along the bottom (enclosed within a grey box) are the number of deaths at each reporting date examined and the fold-increase (in bold) compared to the 8-July baseline.

So with that visualization under our belt, there is another, less laborious way to look at this, by graphing the numbers, rather than the gaps.

What we see when we plot the fold-change values against report date is that total cases lost control as we suspected, but deaths are less obviously out of control. From 9-Sept onwards the gap has widened a little more consistently. Before that though the deaths did not dramatically drift away from the rate at which new cases were being added.

I'll graph Sierra Leone, Guinea and Nigeria in the next day or two. Nigeria should serve as an example of how this looks for a country in which EVD is definitely in control. 

Graphing the control gaps

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